A passage is given with 5 questions following it. Read the passage carefully and choose the best answer to each question out of the four alternatives and click the button corresponding to it.
Acharya Jagadish Chandra Bose, one of the greatest of modern scientists, graduated from St. Xavier.s College, Kolkata. He then obtained Tripos of Cambridge University and joined the Presidency College, Kolkata, as Professor of Physics. He was a pioneer in the discovery of the wireless and radio and the Microwave. He made remarkable contribution to the science of Botany by proving with the help of an instrument of his own invention that not only do trees and plants have life, but feel pleasure and pain as we do. He was perhaps the first scientist to suggest the possibility of gathering and utilising energy from solar rays. Last but not least was the Bjose Institute which he founded in 1917. It has now become a world-famous Research Laboratory doing yeoman.s service to various branches of science.
What is meant by yeoman service?

Options

A. Minimal
B. Invaluable
C. Discreet
D. Sporadic

Answer

B